I have tried searching for these and failed to find answers.

Is there any tool available for facing a rear dropout to make the two parallel? The dropout alignment tools show that they are not aligned. A new hub shows a gap between the left dropout and the hub in some places but not all. This is evident both visually and with a feeler gauge. My thought is a facing tool, much like the old bottom bracket and headset facing tools. The frame in question is a 2014 Kona Zone (made by Dedacciai (spelling?)?) with aluminum dropouts bonded in the carbon frame. If it were a carbon dropout I might try building up with epoxy first. The only thing I have found that I might get to work is a pen mill which I would put on a long shaft with 10mm sleaves to match the dropout slots, with a hand lever like the bottom bracket facers. Why did I check this? My wheels with Bitex hubs were very noisy on the Kona but completely silent on the steel Ritchey Breakaway. Old Shimano cup and cone wheels were silent on either bike. Comments desired.

Is there an easy way to check carbon fiber frame alignment? Old steel frames were built symmetrically* with straight constant outside diameter main tubes so alignment checking was straightforward. I cannot tell as a user if a frame is supposed to be symmetric now, and I am not sure how to measure the wheel, crank, headset and saddle interfaces to check for alignment.

*Although I do not know why the bicycle industry has mostly stayed with the rear rim centered on the rear hub, rather than having the right dropout further from the centerline than the left for large rear sprocket counts.

  • 1
    Imagine dishing wheels correctly if every bike make/model had a different asymmetric offset? Even a few (There would be difference ones for Road and MTB, probably EBike's, fat bikes would be pain. Imagine the problems it would cause wheel builders, calculating spoke lengths needs another parameter. What problem does it really solve bringing the left seat and chain stays in a bit? Last thing we need another thing for the industry to f.. around and design in obsolescence (in this case, old wheels. )
    – mattnz
    Commented Jan 13 at 20:24
  • Why would you expect the bike make/model would dictate the wheel spec, and not the hub manufacturer? But when road hubs diverged from the 110mm track hub decades ago, the tools for wheel and frame builds and service would all have had to change and the only real benefit would have been a shorter distance to the left side bearing, which was not a problem anyway. Commented Jan 15 at 6:12

2 Answers 2


I've never seen a shop-level commercial tool that does faces the dropouts to align them.

If you did this, you'd likely need to do it by way referencing the NDS to the DS, and leave the DS completely alone. Take any material away from the hub contact area on the DS and you'd need to machine the hanger interface to match, since it would be bad to put on a new hanger and have it come out misaligned.

Presuming this is QR we're talking about, I can imagine using ink and a hand scraper to take down the "high" (furthest in) spots on the NDS inner contact. You'd then need to get the outside flat again with it. You could then bond on M10 machined washers with a slot cut out to get the inner surface back down to your target OLD. It's all very sketchy and hypothetical, with the only safety net being bonding in a new dropout at great expense if you can even find someone willing to do it, but I don't see a step in there that wouldn't work at least hypothetically, other than if there wasn't enough base material to do it safely (which if true is a limiting factor no matter how you go about it).

The carbon frames I've dealt with that have this issue have been unfortunate situations, including a high-end bike from a very respectable brand where the QC wasn't apparently as good as it should have been. For better or worse, high-quality internal cam QRs will squash the dropouts a lot more effectively than external, such that your hub might suffer the consequences of misaligned dropouts less but your frame is probably more likely to break.

When traditional basic frame alignment gauges that use the outsides of the tubes as references don't apply, the only choice left is use the head tube and/or BB bores, such as with a proper frame table or jig.


Most bikeframes are still build symetrical. Only in very rare cases like with recumbents, or realy early fatbikes, there have been asymetrical frames, with the rim centered between hub flanges, not centered on the axle.

There is a special tool to check dropout alignment, and adjust them. But those toold are very expensive for a 1 time user. And u can't align a carbonframe like steel, by deforming it in the desired direction. So even if u have the tool, u could only use it to asure u got an error. But u are allready sure about that.

For a diy version, get some m10 streaded rod, some m10 nuts. U could also use a fully threaded rear axle from a scrap bikewheel.Cut this in 2 halves. U basicaly make two half axles each bolted with 2 nuts to 1 side dropout only. Have the middle just a fraction apart. The middle will then show the error, one side will not align properly with the other side.

The axle problems could come from the dropouts not being in the correct plane with the bike, even though they are roughly in the right position offcentre.

To check if the dropouts are off-centered properly a rough test would be to put the rearwheel in the wrong way round, with the cassette to the non chain side. If the rim then is not as nicely in the middle as it was, then something might be wrong, certainly if that problem keeps occuring in the same direction when using different wheels. ( it might also be the wheel that is spoked wrong)

If something is wrong it would not be an easy bending job, fix. It would require altering the carbon frame.

Mostly when there is metal on dropouts in a carbon frame, it is just to prevent damage, and it is a very thin, not solid bit. Milling it, u would quickly hit carbon, and or overheat the epoxy keeping the metal in place doing damage to the bond and or the laminate under the metal.

  • Stupid user interface deletes the comment I made before I logged in. Commented Feb 28 at 16:10
  • And stupoid user interface accepts carriage return as part of the text when I am not logged in, but uses the carriage return to post the comment when I am. STUPID COMPUTER USER INTERFACE DESIGN. YOU CAN DO BETTER. and no this remark is not getting to the people who wrote this sub-optimally. Commented Feb 28 at 16:11
  • I made a tool with a pen mill cutter and a 10mm aluminum rod machined on a 7x10 mini-lathe. I used this by hand, the same way a bottomBracket/headset facing tool is used. I do not recommend this. The pen mill cutter is concave not flat which I did not recognize initially. I do not know the name of cutters/mills that sit on a shaft so you can pilot both sides so I do not know how to get an industrial cutter/mill, nor do I know if all pen mill cutters are concave. Commented Feb 28 at 16:16
  • The 2014 Kona Zone has aluminum dropouts in the carbon frame. The hangers which are outside the frame (the 2014 BMC TMR01 has them inside the frame) do not fit as well as I would like; clamping the wheel moves the derailleur visibly. Shimming and shaving helps. Commented Feb 28 at 16:20
  • The QR will distort the axle as well as the frame. This is less of a problem with cup and cone hubs like most Shimano, but a problem with fixed sealed bearing hubs like Bitex or Extralite. Rapid wheel bearing wear and noise is the result, and why I started down this path. Commented Feb 28 at 16:22

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